The word corona is mostly used in astronomy and it describes a phenomenon that happened especially during eclipse. Corona is a ring of light that we can see around the sun or the moon when eclipse is there.
The phenomenon of corona occurred with the sun is much hotter than even with the visible surface of the sun. The exact mechanism that is responsible for the heating of corona is still a matter of debate but some likely possibilities say that the phenomenon occurred because of the induction of the sun's magnetic field with sonic pressure waves that come from below. The extremely high temperature of corona allows it to have some unusual spectral features and it is this phenomenon that made some scholars suggest, that it contains an unknown element called coronium, but later studies refuted the claim.
The phenomenon of corona occurred with the sun is much hotter than even with the visible surface of the sun. The exact mechanism that is responsible for the heating of corona is still a matter of debate but some likely possibilities say that the phenomenon occurred because of the induction of the sun's magnetic field with sonic pressure waves that come from below. The extremely high temperature of corona allows it to have some unusual spectral features and it is this phenomenon that made some scholars suggest, that it contains an unknown element called coronium, but later studies refuted the claim.